Users have become able to acquire a large amount of content data along with recent developments in information communication networks and storage media. Users are able not only to acquire content data created by themselves but also to acquire content data by way of connection to distribution sites and the like. The content data include various types of content data such as image data, moving image data or music data. The image data are data on still images and the like. The moving image data are data on recorded television programs, recoded video programs, movies, animations, and the like. The music data are data on classical music, popular songs, BGM, and the like.
The number of these content data is huge. Accordingly, a user generally utilizes a search system implemented by a computer in order to search for desired content data from a huge number of content data.
In general, devices configured to search for desired contents for each of these types of contents have been disclosed. For instance, there are a search device configured to search for moving image data (see Patent Document 1, for example), a search device configured to search for music data (see Patent Document 2, for example), and other similar devices. Meanwhile, there is also a method of detecting a refrain section of a song (see Non-patent Document 1, for example).